It would be desirable for automotive styling opportunities to be able to apply a band of colored organic paint around the periphery of an automotive vehicle glass to match the paint color of the vehicle. Presently, organic paints would not be sufficiently adherent to the glass surface to allow their use directly on glass in most commercial applications. The present inventor, in U.S. Pat. No. 5,328,753, disclosed the use of a metal-containing ceramic paint as an interlayer between the glass and organic paint to provide adherence therebetween. The paint was disclosed to have ceramic frit, pigment, an organic vehicle like pine oil, and metal powder. The metal powder was taught to keep the ceramic paint from adhering to the mold during glass shaping operations and hence prevent the formation of surface defects. One drawback with that invention is that the ceramic paint uses organic solvents which are less than environmentally desirable. Further, the ceramic paint, until it is cured at high temperatures, is prone to scratching during handling. Therefore, the use of the ceramic paint to provide adhesion between the glass and the organic paint has drawbacks which make such use less than optimal.
In another U.S. Pat. No. 5,698,026, the present inventor discloses a water based silicate paint useful on automotive glass, such as around the periphery for "black out" of the glass areas. I have now unexpectedly found that the water-based paint can be used to adhere the organic paint to glass but only if the water-based paint is contacted with a silane sensitizer material prior to the application of the organic paint. Use of only the water-based paint on the glass, without sensitizer, was found by the inventor to not provide good adhesion of the organic paint to the glass. The use of the water-based paint to adhere the organic paint to the glass has advantages as compared to using the ceramic paint for that function as in U.S. Pat. No. '753 noted above. That is, the water-based paint can be cured at lower temperatures to avoid distorting the glass and avoids the used of organic solvents which provides commercial and environmental benefits. In addition, I have unexpectedly found that the water-based paint, after it is cured, has a rougher surface than the ceramic paint of the '753 patent which is advantageous to adhering the organic paint thereto. I believe this roughness results from the evaporation of the water during curing. Hence, this improves the adhesion of the organic paint to the sensitized water based paint as compared to only glass treated with a sensitizer.